1. Field of the Invention
The invention relates to a folding roof for a convertible with a canvas top which is attached to a front bow and which can be moved into a rear lowered position with a top mechanism which comprises a side roof rod for opening the folding roof.
2. Description of Related Art
To lower one such conventional folding roof system, ordinarily, the first top part is folded to the rear via joints in the side roof rods and is placed on a second top part. However, the arches of the two top parts are pointed oppositely, and thus, a large lowering height results. In addition, in this type of folding of the top, the inside of the first top part faces upward and could become dirty, so that it is not suitable as a cover of the storage space.
Published International Application WO 97/37866 discloses a kinematic folding roof for a convertible in which a front top part of a three-part frame of the top is moved out of the closed position into the storage position by swivelling parallel via a parallelogram rod arrangement which connects the side roof rods of the front cover part to those of the middle part of the top. In the storage position, the front part of the top is identically cambered, i.e., lies on the middle part of the top with an identically pointed arch. The motion of parallel swivelling of the first part of the top is forcibly coupled via a control lever to the lowering motion of the rear part of the top.
A primary object of the present invention is to devise a folding roof of the initially mentioned type which can be housed in a space-saving manner in the storage space, and in particular, can be moved into a partially open position when driving.
This object is achieved in accordance with the invention by the front bow of the folding roof being guided to move in the lengthwise direction of the roof on both sides on guides of the side roof rod so that, by moving the front bow rearwards along the lateral guides from its closed position in which it adjoins the front cross member, the folding roof can be partially opened into an intermediate position. By moving the front bow, which can also be done when driving, the folding roof can be partially opened for ventilation of the interior. The side roof rods or side members of the frame of the top can thus remain locked in their position on the front cross member and thus maintain the stability of the frame of the top. While by moving the front bow rearwards, the canvas folding roof is placed in the front area of the top, for example, in a Z-shaped fold, the canvas folding roof remains in the rear area of the top, for example, tensioned in its shape by the main bow which cannot be moved on the frame of the folding roof, and on which, the canvas folding roof is fixed, as far as a rear attachment of the canvas folding roof on the equator of the body. By moving the front bow, which conventionally has an arch or a camber, over the section of the folding roof which is likewise cambered and which lies behind it, an equally cambered arrangement results which yields a reduced space requirement when the folding roof is lowered in the storage space. Various intermediate positions of the front bow as far as a defined, maximally opened intermediate position can be set. Of course, the explanations also apply to the opposite sequence of motions when the folding roof is being moved out of the storage space and closed again, and also intermediate positions can be adjusted from this direction of motion. In the closed position, the front bow lies on the cross member on the top edge of the front window of the vehicle or on a comparable vehicle-mounted component, such as the frame of the front window, a wind deflector or a connecting part between the top junctions of the two A columns.
For space-saving accommodation of the folding roof in a storage space, it is advantageous if the side roof rods or side members are each divided into a front and a rear roof rod which, in the closed position of the folding roof, form a top frame which is essentially rigid and which is coupled to the cross member, and in the storage position of the opened folding roof, are released from the rigid lengthwise coupling and accommodated in a compact arrangement. When the coupling is released, the roof rods can be swung around, in, or out in different ways and can be located in different positions which require less space, especially in the lengthwise direction of the vehicle. The rear roof rod can be a fixed lateral part of a roof cassette which contains the main bow with the side parts which are attached on either side.
In one especially practical embodiment, the front bow contains the front roof rods, for example, as integrated components, and it is supported both in its closed position and also in the intermediate position only on the guides of the rear roof rod and can be moved jointly with the front roof rods into an intermediate position. When the top is opened into an intermediate position, thus, the front side roof rods are also unlocked from the cross member and are removed from it. The parts which hold the top frame are, in this case, designed with great stability. Since the front bow is not folded up or swung up, but is pushed barely over the canvas folding roof which lies behind, the area exposed to the wind is small, with the corresponding advantages for the stability of the top when it is partially opened even when driving.
The front bow can be movably supported in its closed position on the guides of the front roof rods and/or on the guides of the rear roof rods, by which different configurations for the support of the front bow can be accomplished.
In one preferred embodiment, when the front bow is displaced from its closed position into an intermediate position, the front roof rods are coupled to the cross member, ensuring high strength and stability of the frame of the top.
Preferably, the front bow is supported in a defined intermediate or end position on the guides of the rear roof rods or the roof cassette so that the front roof rods can be moved into an arrangement with a shortened length relative to the length of the cover to be folded. Here, it is feasible for the front and the rear roof rods to be pivotally joined to one another by a pivot joint, and to lower the folding roof into the down position, the front roof rods are pivoted, especially in or even slightly out. The pivoting motion of the front roof rods can take place in a roughly horizontal vehicle plane, roughly around a transverse axis of the vehicle or around axes which deviate therefrom.
The folding roof, between the front bow and the main bow, can have at least one middle bow which is guided on the guides and to which the canvas top is attached. When moved back into an intermediate position the front bow first moves with the formation of a Z-shaped fold of the canvas top against the middle bow which is fixed on the guide until it is positioned on or essentially over the middle bow. The canvas top remains tensioned in its shape by the middle bow via the main bow to the rear attachment of the canvas top on the equator of the vehicle body. The front bow and the middle bow can then be pushed back further to the main bow as an intercoupled unit. The drive of this bow unit takes place via the front bow, while the middle bow which does not have its own drive is entrained.
In an arrangement which is feasible for lowering the top, each of the rear roof rods or the side parts of the roof cassette are pivotally mounted on the body via a respective parallelogram-like four-bar arrangement which contains a main column and a main connecting rod. An electrical or hydraulic main drive acts, for example, on the main column, and moves the entire four-bar arrangement and thus the folding roof via the main column.
The front roof rods do not need their own drive if the four-bar arrangement is coupled via a connecting rod means to the front roof rod, and during its pivot motion to lower the cover into the lowered position, it swings in the front roof rod via this connecting rod means.
In one simple configuration, the connecting rod of the connecting rod means, on the one hand, is pivotally coupled to a projection of the main connecting rod which projects via its hinged connection to the rear roof rod, and on the other hand, is coupled to the front roof rod or to an auxiliary rod arrangement of the roof rod connected in between.
Another embodiment calls for the connecting rod means to be driven by the pivoting main column of the four-bar arrangement; however, the main connecting rod can also be used as the drive. Because the connecting rod means is coupled via a lock means to the main column over the defined pivot path of the main column in a driving engagement, it is possible to fix the initial pivot position and the end pivot position of the main column which determine the area in which the connecting rod means, as a pivot drive, is in an active driving connection when the folding roof is folded in or out. Instead of the main column, the lock means can also couple the connecting rod means to the main connecting rod according to one alternative embodiment.
An arrangement is especially preferred in which pivoting of the left and the right front roof rods is staggered in time by the connecting rod means. In this way, the two pivoting roof rods can be swung in one after the other from the left and the right top side into a cross position without mutual hindrance, for example, on or underneath the main bow or the roof cassette. The pivoting roof rods can thus have a greater length which, for example, corresponds roughly to the width of the folding roof.
Feasibly, the connecting rod means provides a varying drive speed for the front roof rod. Thus, for example, translation of the motion of the connecting rod means can be designed such that the pivoting speed of the roof rod is adjusted depending on the pivoting speed of the main column and is variable over the pivot path. Thus, at the start and at the end of the pivot motion, a comparatively slow speed can be set for lowering the roof rods on the roof cassette or for coupling to the front cross member, and in between, a higher speed can be used.
Preferably, the connecting rod means contains a ring which is pivotally mounted concentric to the pivot bearing axis of the main column and bordering the main column. This ring is drive-coupled via its lever arm and via intermediate rods and hinges of the connecting rod means to the roof rod.
Furthermore, the lock means can have a lock pin which is supported to be able to move axially in the ring, and depending on the pivot position of the main column relative to the roof cassette side part, is pushed into coupling engagement with the main column.
Stops, such as pins, projections and the like can be provided to limit a path of motion of the connecting rod means, especially the lever arm of the ring.
For a uniform and space-saving arrangement of the roof rods which are swung in crosswise, it is advantageous if the pivot joints of the roof rods, which have a vertical swivel axis and which are located on the two-sided roof cassette side parts, are offset relative to one another in the lengthwise direction of the vehicle, the amount of offset, for example, corresponding roughly to the thickness of the roof rods. Thus, also longer roof rods can be swung into the down position in a space-saving manner.
In one alternative embodiment, the front bow, as it continues to move backwards from a defined intermediate position, activates an auxiliary rod arrangement via which the front roof rods are pivoted or swung in. By means of this forced coupling, a separate drive is likewise unnecessary. However, there can also be an additional drive which pivots the front roof rods, and pivoting can take place independently of the position or movement of the front bow or other components of the folding roof.
The drive for the front bow is preferably located on the rear roof rod or the main bow and is connected to the front bow via a coupling such as, for example, cable pulls or Bowden cables. These arrangements of the drive allow a configuration of the roof headliner with minimum possible adverse effects on the head space for the vehicle passengers.
In one practical configuration, it is provided that one displacement motion of the front bow at a time out of an opened, defined intermediate position, locks or unlocks a lock means to fix the roof rods on the cross member. Thus, locking and unlocking of the frame of the top takes place on the cross member as long as the canvas top is untensioned in the front top area. While, in conventional folding roof systems, the last closing motion of the cover, at the same time, encompasses the tensioning of the entire canvas top and the actuation of the locking means, for which hydraulic force drives are necessary, in this configuration, more weakly dimensioned electric drives can execute the locking and tensioning of the front section of the canvas cover which take place after one another.
The front bow can be supported on the guides by means of the sliding elements or also by combinations of sliding and rolling elements.
When the guides have gradient sections, with a corresponding arrangement of these gradient sections, the front bow can be raised out of its closed position during opening and can be guided over the canvas top which lies behind.
The front roof rods can each be composed of two successive roof rod elements which are connected to one another by a joint. In this way, longer folding roofs can be lowered by repeated subdivisions of the side rods, likewise, in a compact arrangement.
In the described cover mechanism, the front bow can be made as a cover for a storage space of the top since its surface always faces up.
These and further objects, features and advantages of the present invention will become apparent from the following description when taken in connection with the accompanying drawings which, for purposes of illustration only, show several embodiments in accordance with the present invention.